Support attached_textN/attached_fileN

Issue #437

internal/forms/builder.go

@@ -132,13 +132,24 @@ func (b messageBuilder) buildXML() []byte {
 
 func (b messageBuilder) buildAttachments() []*fbb.File {
  var attachments []*fbb.File
-
- // Add FormData.txt attachment if defined by the form
- if v, ok := b.FormValues["attached_text"]; ok {
- delete(b.FormValues, "attached_text") // Should not be included in the XML.
- attachments = append(attachments, fbb.NewFile("FormData.txt", []byte(v)))
+ // Add optional text attachments defined by some forms as form values
+ // pairs in the format attached_textN/attached_fileN (N=0 is omitted).
+ for k := range b.FormValues {
+ if !strings.HasPrefix(k, "attached_text") {
+ continue
+ }
+ textKey := k
+ text := b.FormValues[textKey]
+ nameKey := strings.Replace(k, "attached_text", "attached_file", 1)
+ name, ok := b.FormValues[nameKey]
+ if !ok {
+ debug.Printf("%s defined, but corresponding filename element %q is not set", textKey, nameKey)
+ name = "FormData.txt" // Fallback (better than nothing)
+ }
+ attachments = append(attachments, fbb.NewFile(name, []byte(text)))
+ delete(b.FormValues, nameKey)
+ delete(b.FormValues, textKey)
  }
-
  // Add XML if a viewer is defined for this template
  if b.Template.DisplayFormPath != "" {
  filename := xmlName(b.Template)